Novel photographic processes and products

ABSTRACT

This invention relates to photographic processes for producing color images by reacting (a) a dye intermediate containing a carbonyl group and selected from an aldehyde and a ketone with (b) a color-forming reagent to form a complete dye wherein an imagewise distribution of at least one of said dye intermediate and said color-forming reagent is formed as a function of developing an exposed silver halide layer followed by reacting the color-forming reagent with the carbonyl group of the dye intermediate to form a corresponding imagewise distribution of a complete dye. In a preferred embodiment, a sulfur-nitrogen compound capable of undergoing cleavage in the presence of silver ions and/or soluble silver complex made available as a function of development is used to release one or both of the dye-forming reagents in an imagewise distribution corresponding to said silver ions and/or said complex.

United States Patent 91 Locatell, Jr. et al.

I NOVEL PHOTOGRAPHIC PROCESSES AND PRODUCTS [75] Inventors: Louis Locatell, Jr., Wellesley Hills; Frank A. Meneghini, Belmont; Howard G. Rogers, Weston, all of Mass.

[73] Assignee: Polaroid Corporation, Cambridge,

Mass.

[22] Filed: June 21, 1971 21 Appl. No.: 155,000

UNITED STATES PATENTS Porter et al ..96/36 1 March 6, 1973 Primary Examiner.l. Travis Brown Assistant ExaminerAlfonso T. Suro Pico Attorney-Charles Mikulka et al.

57 ABSTRACT This invention relates to photographic processes for producing color images by reacting (a) a dye intermediate containing a carbonyl group and selected from an aldehyde and a ketone with (b) a color-forming reagent to form a complete dye wherein an imagewise distribution of at least one of said dye intermediate and said color-forming reagent is formed as a function of developing an exposed silver halide layer followed by reacting the color-forming reagent with the carbonyl group of the dye intermediate to form a corresponding imagewise distribution of avcomplete dye. In a preferred embodiment, a sulfur-nitrogen compound capable of undergoing cleavage in the presence of silver ions and/or soluble silver complex made available as a function of development is used to release one or both of the dye-forming reagents in an imagewise distribution corresponding to said silver ions and/or said complex.

51 Claims, 2 Drawing Figures NSPARENT SUPPORT SULFUR- NITROGEN COM POUN D COLOR-FORMING REAGENT SILVER HALIDE EMULSION NG COMPOSITION SHEET SUPPORT SILVER HALIDE EMULSION PROCESSING COMPOSITION SULFUR-NITROGEN COMPOUND COLOR-FORMING REAGENT TRANSPARENT SUPPORT PATENTEDKAR @1915 3,719,488

r TRANSPARENT SUPPORT Y Z [4d i su.vm HALIDE EMULSION l5 EH-5331 3351: PROCESSING COMPOSITION |3 N SPREADER SHEET SUPPORT SI LVER HALIDE EMULSION phoccssms COMPOSlTION SULF -NITROGEN COMPOUND COLOR- MING REAGENT TRANSPARENT SUPPORT IN VENTORSI LOUIS LOCATELL JR. FRANK AMENEGHINI and BY HOWARD 0. ROGERS Mum and 7724M ATTORNEYS NOVEL PHOTOGRAPHIC PROCESSES AND PRODUCTS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to processes for the formation of photographic images and, more particularly, to the production of dye images and to photographic products useful therein.

2. Description of the Prior Art Diffusion transfer photographic processes are now well-known. In preparing silver images according to such processes, an exposed photosensitive element comprising a light-sensitive silver halide emulsion is developed by treating the emulsion with a processing composition comprising an aqueous alkaline solution of a silver halide developing agent and a silver halide solvent. The developable silver halide of the emulsion is reduced to image silver by the developing agent while the silver halide solvent forms an imagewise distribution of a soluble silver complex with the undeveloped silver halide. This imagewise distribution of soluble silver complex is, at least in part, transferred by imbibition to a superposed image-receiving layer where it is reduced to form a silver transfer image.

Copending U. S. Patent Application of R. F. W. Cieciuch, R. R. Luhowy, F. A. Meneghini and H. G. Rogers, Ser. No. 155,123, filed concurrently herewith, describes and claims photographic processes employing certain photographically inert compounds which are stable in'the photographic processing composition but capable of undergoing cleavage in the presence of the imagewise distribution of silver ions made available during processing of a silver halide emulsion to liberate a reagent, such as, a photographically active reagent or a dye in an imagewise distribution corresponding to that of said silver ions. Depending upon the photographic process and this results it is desired to achieve, the inert parent compound may be diffusible or substantially non-diffusible in the processing solution and the reagent liberated also may be diffusible or substantially non-diffusible in the processing composition.

In one embodiment disclosed in the aforementioned application, color images are produced by using as the photographically inert compounds, color-providing compounds which are substantially non-diffusible in the photographic processing solution but capable of undergoing cleavage in the presence of the imagewise distribution of silver ions and/or soluble silver complex made available in the undeveloped and partially developed areas of a silver halide emulsion as a function of development to liberate a more mobile and diffusible color-providing moiety in an imagewise distribution corresponding to the imagewise distribution of said ions and/or said complex. The subsequent formation of a color image is the result of the differential in diffusibility between the parent compound and liberated color-providing. moiety whereby the imagewise distribution of the more diffusible colorproviding moiety released in undeveloped and partially developed areas is free to transfer.

Amoung the compounds disclosed as useful in liberating a reagent in the presence of silver ion are sulfur-nitrogen compounds containing the group,

wherein X is These compounds may be linear or cyclic in structure, and when cyclic, either or both the S and N atoms may be constituents of the ring. Particularly useful are cyclic compounds containing the group as part of the ring. and preferably, the latter. Like 1,3- I

As discussed in the aforementioned copending application, sulfur-nitrogen compounds, as exemplified by thiazolidine compounds, exhibit good stability in alkaline media, such as the aqueous alkaline processing compositions employed in conventional tray and diffusion transfer photographic processes, and undergo cleavage in the presence of silver ions and/or soluble silver complex made available during processing to release a reagent as a smaller molecule in an imagewise distribution corresponding to the imagewise distribution of silver ions and/or soluble silver complex. For example, thiazolidine compounds release a diffusible dye such that a diffusion transfer image is obtained in reasonable processing times. In one aspect, the present invention is concerned with utilizing the sulfur-nitro gen compounds defined above for releasing a substantially colorless and preferably a colorless dye intermediate selected from an aldehyde and a ketone for further A reaction with a color-forming reagent to form a dye image.

SUMMARY OF THE INVENTION According to the present invention, it has been found that the reaction of an aldehyde or a ketone with a color-forming reagent, e.g., a methylene coupler may be utilized in a photographic system to form a dye image. Further, it has been found that the above sulfurparticularly as part of a ring system may be used to release one or both of these reagents in an imagewise distribution, which reagents upon subsequent reaction produce a corresponding imagewise distribution of a complete dye. Typical cyclic sulfur-nitrogen compounds are illustrated in the following formulas:

a complete dye directly from such compounds, it is surprising that' a photographic image may be obtained using a two-step procedure of liberating'one or both of the reagents from a sulfur-nitrogen compound followed by reaction of these reagents to yield a dye image.

It is, therefore, the primary object of the present invention to provide a process for preparing a dye image by reacting a dye intermediate containing a carbonyl group and selected from an aldehyde and a ketone with a color-forming reagent to form a complete dye, one of said color forming reagent or said dye intermediate being provided inan imagewise distribution as a function of development of a silver halide layer.

Another object of the present invention is to provide such a process employing a sulfur-nitrogen compound which undergoes cleavage in the presence of an imagewise distribution of silver ions and/or soluble silver complex made available as a function of development of a silver halide layer to release the dye intermediate as an aldehyde or ketone.

A further object of the present invention is to provide photographic products useful in processes for producing an imagewise distribution of said dye intermediate which products contain a sulfur-nitrogen compound which upon cleavage in the presence of ionic silver, i.e., silver ions and/or soluble silver complex made available during processing of a silver halide layer releases said dye intermediate in an imagewise distribution corresponding to the iniagewsie distribution of said silver ions and/or said-soluble silver complex. I I Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing.

1 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an enlarged, diagrammatic, fragmentary section view illustrating the preparation of a color image according to one aspect of this invention; and

FIG. 2 is a similar view illustrating another aspect of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As noted above, dye images are prepared in accordance with the present invention by reacting (a) a dye intermediate containing a carbonyl group and selected from an aldehyde and a ketone with (b) a color-forming reagent to form a complete dye which comprises the steps of developing an exposed silver halide layer with an aqueous alkaline processing composition; forming as a function of development, an imagewise distribution of at least one of said dye intermediate and said color-forming reagent; and thereafter reacting said color-forming reagent with the carbonyl group of said dye intermediate to form a corresponding imagewise distribution of a complete dye. The desired imagewise distribution of dye-forming reagents may be achieved by using a sulfur-nitrogen compound which upon cleavage in the presence of ionic silver releases the dye intermediate and/or color-forming reagent, as desired. The two-step reaction of releasing an aldehyde or a ketone from, e.g., a cyclic 1,3-sulfur nitrogen compound followed by reacting the released aldehyde or ketone with a color-forming reagent, such as,- a methylene coupler proceeds according to the following sequences:

While either the dye intermediate or color-forming re agent, or both may be diffusible in the processing composition, a complete dye may be formed even when both reagents are relatively non-diffusible.

According to one embodiment of the present invention, the sulfur-nitrogen compound is situated in a layer associated with a light-sensitive silver halide layer, e.- g., a silver halide emulsion carried on a support which emulsion, after being exposed, is developed in the presence of. a color-forming reagent with an aqueous alkaline processing composition including a silver halide developing agent and a silver halide solvent. The imagewise distribution of silver ions and/or soluble silver complex made available during processing of the emulsion migrates to the associated sulfur-nitrogen compound which, preferably, is non-diffusible in the processing composition, and the sulfur-nitrogen compound undergoes cleavage in the presence of said ions and/or said complex to provide a corresponding imagewise distribution of dye intermediate. The imagewise distribution of dye intermediate thus formed reacts with the color-forming reagent to produce a corresponding imagewise distribution of a complete dye which may be transferred by imbibition 'to an imagereceiving layer depending upon its diffusibility in the processing com position.

According to another embodiment of the present invention, the color-forming reagent rather than the dye intermediate is provided in an imagewise'distribution as a function of development and subsequently the colorforming reagent reacts imagewise with a dye intermediate to produce the dye image. An imagewise distribution of color-forming reagent may be obtained, for example, by selecting a color-forming reagent capable of reacting with the oxidized portions of developing agent, or conversely, by using a color-forming reagent capable of reacting with the unoxidized portions of the developing agent.

As indicated above, the sulfur-nitrogen compound may be employed to release the color-forming reagent in an imagewise fashion. If desired, an appropriately substituted sulfur-nitrogen compound may be employed which upon cleavage in the presence of the imagewise distribution of ionic silver provides both the color-forming reagent and dye intermediate for subsequent reaction to produce the complete dye.

When a 1,3-sulfur-nitrogen compound is used to provide the imagewise distribution of dye intermediate and/or color-forming reagent, for example, to release an aldehyde dye intermediate, one of the hydrogens on the carbon atom common to the S and N atoms is substituted with a group which, when released as an aldehyde is substantially colorless and is capable of reacting with a color-forming reagent, such as a methylene coupler, to form a complete dye. The substituent selected may comprise any hydrocarbon radical, substituted or unsubstituted, provided the aldehyde released upon cleavage functions as a dye intermediate, i.e., it is capable of reacting with the selected colorforming reagent to yield a complete dye. Where it is desired to release a ketone dye intermediate, both hydrogens in the 2-position, i.e., on the carbon atom common to the S and N atoms are replaced with groups which, upon cleavage of the parent compound, provide a ketone which is substantially colorless and is capable of reacting with a color-forming reagent, e.g., a methylene coupler to form a complete dye. As in the case of the aldehyde dye intermediate, the two groups selected may comprise any hydrocarbon radical providing the foregoing criteria are satisfied. The nitrogen of the parent sulfur-nitrogen compound may be substituted with hydrogen, or if desired, with a hydrocarbon radical.

Rather than being linked directly to the carbon atom in the 2-position of the parent compound, the 2-substituent (s) may be linked indirectly thereto through an appropriate linking group which may be acyclic or cyclic. Typical linking groups include cycloalkyl, such as cyclohexyl; CONl-l; alkyleneCONH-; arylene-CONl-l; alkylene; and arylene wherein alkylene may be ethylene, propylene, butylene and arylene may be phenylene. By the term dye intermediate as used herein, it is intended to include any linking group, and said aldehydes and ketones are intended to include polynuclear aromatic compounds, e.g., 4-dimethylaminonaphthaldehyde.

To release a color-forming reagent, the appropriate moiety may be substituted in the 2-position or in another position on the parent compound either directly or through a linking group, such as those enumerated above. For example, a moiety comprising a methylene coupler may be substituted in the 4-position and if desired, an appropriate hydrocarbon radical(s) may be substituted in the 2-position that will yield an aldehyde (or ketone) dye intermediate upon cleavage of the parent compound so that an imagewise distribution of both aldehyde (or ketone) and color-forming reagent is obtained that corresponds to the undeveloped and partially developed areas of the silver halide layer.

Where it is desired to render the parent compound substantially non-diffusible in the processing solution, the compound may be substituted with an immobilizing group or anchor. Rather than a single immobilizing group, the parent compound may be substituted with two or more groups which together preclude migration of the compound from its position in the photographic element. Where it is desired that the liberated reagent, e.g., aldehyde dye intermediate be di'ffusible, the immobilizing groups will be positioned so that they will not interfere with the mobility of the releasedsaldehyde in the processing solution. For example, when several groups together are used to immobilize the compound, one or more of the groups may be on the fragment ultimately released as the dye intermediate so long as the group(s) does not reduce to any unacceptable extent its mobility and diffusibility in the processing composition. When only a single immobilizing group is used to anchor the parent compound, its position on the parent compound should be such that it will not be on the portion to be released as the diffusible dye intermediate.

The selection of a particular immobilizing group(s) for anchoring the parent compound will depend primarily on whether it is desired to employ only one immobilizing group or to employ two or more groups which together are capable of anchoring the compound. Where two or more groups are employed to immobilize the compound, lower alkyl groups, butyl or propyl, for example, may be used. Where only one group is used to immobilize the compound, it is customary to employ, for example, a higher alkyl radical such as octyl, decyl, dodecyl, stearyl, and oleyl or a substituted or unsubstituted carbocyclic or heterocyclic ring having six members or more in the ring. Where cyclic compounds are employed, the carbocyclic or heterocyclic immobilizing group may be bonded to a single carbon atom or to adjacent carbon atoms of the parent compound.

As noted above, for liberating a dye intermediate, the sulfur-nitrogen compound, such as, a l,3-sulfur- 7 nitrogen compound is appropriately substituted with a hydrocarbon radical(s) that will provide upon cleavage of the parent compound, an aldehyde or ketone capable of reacting with a color-forming reagent. Useful hydrocarbon radicals include aliphatic, cycloaliphatic, aromatic and heterocyclic radicals. These radicals may possess ethylenic or acetylenic unsaturation, and the carbon chains may be interrupted by heteroatoms or heteroatom groups, such as S, O, N, SO, NH and so forth. Also, the radicals may contain substituents, e.g., phenyl, alkyl, alkyl ether, aryl ether, carbalkoxy, carboxy, hydroxy, sulfo, halo, cyano, nitro, and alkylamino. For example, it may. be desirable to use a hydrocarbon radical containing solubilizing groups, such as COOl-l or HSO to enhance diffusibility of the dye intermediate released.

Examples of useful hydrocarbon radicals are substituted and unsubstituted alkyl groups, such as, methyl, ethyl, octyl, dodecyl; substituted and unsubstituted cycloalkyl radicals, such as, cyclohexyl, cyclopentyl, cyclooctyl; substituted and unsubstituted alkenyl groups, such as, vinyl, allyl, butenyl, decenyl, octadienyl, heitatrienyl; substituted and unsubstituted cycloalkenyl groups, such as, cyclopentenyl, cycloheptenyl, cyclohexadienyl; substituted and unsubstituted alkynyl groups, such as, ethynyl, hexynyl, octynyl; substituted and unsubstituted aryl radicals, such as, phenyl, tolyl, benzyl and naphthyl; and substituted and unsubstituted heterocyclic groups, such as those having a 4-,5- or 6-membered ring and containing 0, N, S, and combinations thereof derived from, e.g., pyrrole, pyrazole, oxazole, thiazole, imidazole, pyrimidine, piperidine, piperazine, thiophene, pyrrolidine, azetidine.

The parent sulfur-nitrogen compound also may contain substituents other than those required to provide the appropriate dye intermediate which do not interfere with the intended photographic use of the compound. Such substitutents include carboxy, sulfo, nitro, hydroxy, halo, e.g., chloro and bromo, cyano and hydrocarbon radicals such as those enumerated above including aliphatic, cycloaliphatic, aromatic and heterocyclic radicals which may be saturated or unsaturated, which may contain carbon chains interrupted by heteroatoms or heteroatom groups and which may be substituted or unsubstituted.

While the sulfur-nitrogen compound may be used to liberate a color-forming reagent, the compound usually is employed to release the aldehyde or ketone dye intermediate in an imagewise distribution which aldehyde or ketone then reacts with a color-forming reagent present in a layer of the film unit and/or in the processing composition. As the color-forming reagent, any compound may be used that will react with aldehydes and/or ketones to give a colored product. Suitable compounds include methylene couplers and those reagents used in color tests for identifying aldehydes and ketones as reported in the literature. The term methylene coupler as used herein is intended to include compounds containing an active methylene group and also compounds containing a reactive methyl group capable of forming a methylene base in alkaline media. Typical of compounds possessing a reactive methyl group are quaternary ammonium com pounds, such as, pyridinium quaternary ammonium compounds having a methyl substituent in the 2 and 4 positions of the heterocyclic ring. Examples of 2 and 4 methyl-substituted pyridinium compounds are those wherein the nitrogen atom is substituted by groups, such as, alkyl, e.g., methyl, ethyl and propyl; aryl, e.g., phenyl; and aralkyl, e.g., phenethyl and benzyl. These compounds may be used as the free base or a salt where the anion is a derivative of any acid, e.g., a tosylate.

The couplers containing an active methylene group may be characterized as compounds containing a methylene (-CH group bonded directly to at least one activating group, such as, a keto, aldehyde, ester or nitrile group and usually a carbonyl or nitrile group. The methylene group also may be bonded to two such activating groups, the same or different, and the methylene group may be part of an open chain structure or a member of a ring system. Also, the coupler may contain more than one methylene group, e.g., a bis coupler.

These compounds containing at least one active methylene group are generally known in the photographic art as useful couplers with color developing agents, e.g., the pphenylene diamine series, to form a dye, as discussed in Mees, The Theory of the Photographic Process, revised edition, l966, pp. 382-395. Any of the methylene couplers commonly used for this purpose may be employed in the present invention such as the acylacetic esters; acylacetoacetic esters; malonic acid esters; acetonitriles; acylacetonitriles, aroylacetonitriles; cyanacetic esters; cyanacetophenones; cyanacetyl coumarones;

cyanacetyl hydrazones; acetoacetamides; cyanoacetamides; 1,3-indandiones; thioindoxyls; oxindoles; indazoline-3-ones; isoxazole-S-ones; pyrimidazolones; and homophthalimides. Though the coupler employed usually is colorless, a coupler having its own color, e.g., a coupling dye as described in U. S. Pat. No. 3,087,817 may be used to obtain, for example, a more desirable color as may be appropriate or desired.

Examples of methylene couplers of the foregoing description which are useful in the practice of the present invention include:

. N-methyl-a-picolinium tosylate N-methyly-picolinium tosylate N-methoxy-Z-picolinium methosulfate N-ethyl-y-picolinium bromide N-benzyl-2-picolinium bromide N-methyl-2-methylquinolium chloride N-phenyl-Z-methylquinolium chloride 4-(n-octadecylaminocarbonyl)-N-( l-phenyl-S- pyrazolyl-3 )phthalimide 9. a-(m-nitrobenzoyl)-2-methoxyacetanilide l0. a-pivalylacetanilide l l. acetoacetanilide l2. benzoylaceto-2-methoxy-5-dodecyl oxycarbony] anilide l3. benzoylacetone l4. B-naphthoylacetone l 5 2-( a-cyanoacetyl )-coumarone l6. Z-cyanoacetyl-S-sulfondimethylamide l7. benzoylacetic ester 18. cyanoacetylhydrazone of acetoacetic ethylester 19. ethylacetoacetate 20. ethyl-a-benzoyl-a-fluoroacetate 2i 3-( stearoylacetamido )-isophthalic acid 22. N,N'-di-(acetoacetamino)diphenyl cyanoacetophenone 23. p-nitrophenylacetonitrile 24. benzoylacetonitrile 25. bromothioindoxyl 26. l-cyanocetamino-benzothiazole 27. e-phenylisoxazol-S -one 28. pyrimidazolone 29. N-ethyloxindole 30. indazolin-3-one 31. thioindoxyl 32. 1,3-indondione 3 3. N-phenyl-/3-andinoglutaconimide 34. N-phenylhomophthalimide 35. l,3-diethylthiobarbituric acid Depending upon 'the particular procedure used to form the dye image, the color-forming reagent selected may be either diffusible or non-diffusible, i.e., it may be capable of diffusing in the processing composition and through the photosensitive and other layers of the photographic element, or it may be substantially immobile in the processing composition and non-migratory from its initial position in the photographic element. A method commonly employed to render the color-forming reagent, such as the aforementioned methylene couplers non-diffusing is to introduce into the compound, a bulky substituent such as a long chain alkyl as discussed above for use in anchoring the parent sulfurnitrogen compound. The non-diffusible couplers may have, in addition, a salt-forming group, e.g., a carboxyl or sulfo group whereby the couplers may be more readily incorporated into the desired layer of the photographic element. Alternatively, the non-diffusible coupler may be incorporated into the desired layer by dispersion techniques using high and/or low boiling sol-- vents. It will be appreciated that the bulky substituent and salt-forming group when employed will be positioned on the molecule in a non-coupling position.

The color-forming reagent may be present initially in the photosensitive element, e.g., in the silver halide emulsion layer or in a separate layer behind and/or in a separate layer coated over the emulsion layer; in the image-receiving element, e.g., in the dyeable stratum itself or in a layer thereover; or in the processing composition. The parent sulfur-nitrogen compound may be present initially in the photosensitive element in the emulsion layer or in a separate layer behind and/or coated over the silver halideemulsion layer, or in the image-receiving element in the dyeable stratum or in a separate layer associated therewith and may be in the same layer of the photographic element as the colorforming reagent or in a different layer. When the parent sulfur-nitrogen compound and/or color forming reagent are incorporated into the silver halide emulsion layer itself, these reagents should be photographically innocuous in the respect that they do not adversely affect or impair image formation, at least to any appreciable extent. If not photographically innocuous, the reagents may be modified in such manner which does not interfere with the development process in any way but which deactivates the reagents so that they do not affect adversely the light-sensitive emulsion.

It will be appreciated that the initial position of the color-forming reagent and sulfur-nitrogen compound in the photographic element and the selection of particular color-forming reagent and aldehyde or ketone intermediate to form either a diffusible or non-diffusible dye will depend upon the results it is desired to achieve. For example, in preparing monochromatic images in the photosensitive element, the sulfurnitrogen compound may be present initially in the photosensitive element and also the color-forming reagent, or the color-forming reagent may be present in the processing composition. Where it is desired to form the image in an image-receiving element, the parent compound may be present initially in the photosensitive or image-receiving element and the color-forming reagent may be in either the photosensitive or imagereceiving element or in the processing composition. Depending upon the mobility characteristics required, the color-forming reagent employed may be non-diffusible initially, or it may be initially diffusible.

According to a preferred embodiment of the present invention, multichromatic images are prepared. For example, the above-described compounds may beemployed in photographic systems utilizing integral multilayer photosensitive elements comprisingat least two selectively sensitized silver halide strata which are processed simultaneously and without separation: to provide a multi-color image which may be transferred by imbibition to a single common image-receiving element. In this system, the desired color-forming reagent and sulfur-nitrogen compound capable of releasing the desired aldehyde or ketone dye intermediate are associated with each of the light-sensitive silver halide strata. Preferably, the color-forming reagent and parent sulfur-nitrogen compound are used in admixture in a layer separate from the emulsion layer which layer may be separated from the emulsion by one or more spacer layers. The complete dye formed may be non.- diffusible so that the color image remains in the photosensitive element, or the complete dye formed may be diffusible and thus, capable of being transferred to the image-receiving element to form a color image thereon. To prevent the undesirable migration of silver ions as contained in soluble silver complex from one silver halide stratum to another during processing, spacer or interlayers containing a silver ion scavenger may be employed.

Besides forming a dye of the desired color, the complete dyes formed may be colorless or of a color other than that ultimately desiredin acertain environ-v ment, such as at a particular pH level, but upon'a change in environment, e.g., from acid to alkaline conditions, take on a color change.ltis also conternplated that the complete dye formed ma y be a temporarily shifted dye, i.e., a dye which undergoes a color shift or a change in spectral absorption characteristics after processing. The complete dye produced also may be a metal complexable dye, the non-complexed form of which is substantially colorless, but which, upon being complexed subsequent to image formation, is of the desired color. 1

The processing compositions comprise an aqueous alkaline solution of a silver halide developing agent and preferably contain a silver halide solvent, though it is not essential. The named ingredients may be present initially in the aqueous medium or may be present initially elsewhere in the photographic product, for example, in the emulsion and/or image-receiving and/or spacer layers as heretofore suggested in the art. When such ingredients are present initially in the film unit, the processing'composition is formed by contacting the product with a suitable aqueous medium to form a solution containing these ingredients.

The alkali employed in the processing composition may be any of the alkaline materials heretofore used,

such as sodium or potassium hydroxide. The silver halide solvent also may be any of the heretofore known materials, such as sodium or potassium thiosulfate, sodium thiocyanate or uracil. Also, a silver halide solvent precursor may be used, such as described in copending U. S. Pat. application Ser. No. 99,310 filed Dec. 17,1970.

The silver halide developing agent may be selected from those commonly employed, such as the diamino benzenes, e.g., paraphenylenediamine; aminophenols,

e.g., methyl-p-aminophenol; and dihydroxybenzenes,

e.g., hydroquinone. in addition to the aforementioned ingredients, the composition may contain antifoggants, preservatives, viscosity-imparting reagents, and other adjuncts as conventionally employed. It will be understood that the selection of the above materials is not critical to the practice of this invention.

In the accompanying drawings, FIG. 1 illustrates the processing of a photosensitive element to prepare a dye image according to one embodiment of the present invention. As shown therein, an exposed photosensitive element including a transparent support 10, a layer 11 comprisinga mixture of (a) a color-forming reagent and (b) a sulfur-nitrogen compound capable of releasing a dye intermediate selected from an aldehyde and a ketone and a light-sensitive silver halide emulsion layer 12 is placed in superposition with a spreader sheet 13. A processing composition 15 comprising an aqueous alkaline solution of a silver halide developing agent and a silver halide solvent is distributed between the two elements as they are brought into superposition. In exposed areas of emulsion layer 12, silver halide is reduced to image silver while an imagewise distribution of soluble silver complex is formed in terms of unexposed areas. This irnagewise distribution is, at least in part, transferred by imbibition to layer 11 where it accelerates cleavage of the sulfur-nitrogen compound to release the dyeintermediate in areas corresponding to unexposed areas'of emulsion layer 12. The released dye intermediate, in turn, reacts with the associated colorforming reagent to produce an imagewise distribution of non-diffusible dye corresponding to unexposed areas of the emulsion layer, thereby producing a color image therein.

Processing composition 15 may be applied to the emulsion layer by coating, dipping, spraying or any or all of the ingredients thereof may be confined initially in a frangible container such as disclosed in U.S. Pat. No. 2,543,181, the container being positioned in the film unit so as to be capable upon rupturing of spreading its contents in a substantially uniform layer between the superposed layers. It will be appreciated that the respective elements may be placed in superposition following impregnation with the processing composition according to procedures known in the art.

Color transparencies also may be obtained by employing a film unit where the layer of color-forming reagent and sulfur-nitrogen compound capable of liberating the dye intermediate is associated with the receiving element, such as illustrated in FIG. 2. As shown therein, an exposed silver halide emulsion 12 on a support is processed by spreading a processing composition 15 such as defined above between the emulsion layer and a layer 11 of color-forming reagent and sulfur-nitrogen compound carried on a transparent support 14. In exposed areas of emulsion layer 12, silver halide is reduced to image silver, while an imagewise distribution of soluble silver complex is formed in terms of undeveloped areas of silver halide. This imagewise distribution is transferred, at least in part, by imbibition, to layer where it accelerates cleavage of the sulfur-nitrogen compound to provide an aldehyde or a ketone dye intermediate in areas corresponding to undeveloped areas of the emulsion layer. Reaction of the released dye intermediate with the associated color-forming reagent provides a color image directly on the transparent support.

The film structures shown in the Figures may be varied, for example, by employing one or more interlayers between those of the emulsion and the dyeproducing reagents, by varying the order of the layers, or by placing the reagents in separate layers, etc., and is intended to be illustrative only of product structures useful in the preparation of color transparencies according to the present invention. It will be appreciated that dye images prepared in accordance with the present invention also may be viewed as reflection prints by employing a translucent layer of material providing the requisite background for viewing the image, such as a layer of white pigment, e.g., titanium dioxide.

The following examples are given to illustrate the present invention and are not intended to limit the scope thereof.

. v. EXAM LE... Malononitrile and Z-(p-dimethylaminophenyl)-3- propylthiazolidine,

. s I r Water 100.0 cc. Hydroxyethyl cellulose 3.4 g. Sodium hydroxide 5.0 g. Titanium dioxide 50.0 g. Potassium thiocyanate 4.0 g.

Almost instantaneously, a yellow image was produced in the area of the coated sheetcorresponding to the undeveloped portion ofthe photosensitive element. Substantially no yellow dye was visible in the area of the coated sheet, i.e.,.receiving element corresponding to the portion of the photosensitive element where silver had been developed.

EXAMPLE 2 Example 1 was repeated except that N-ethyl-oxindolewas substituted for the malononitrile. A yellow image appeared only in the area of the receiving element corresponding to the undeveloped portion of the photosensitive element.

EXAMPLE Example 1 was repeated except that the sulfurnitrogen compound and color-forming reagent employed were:

respectively. A magenta image was formed in the receiving element only in the area corresponding to the undeveloped portion of the silver halide emulsion.

It will be apparent from the foregoing that compounds containing more than one -SXN= or group, such as the compound used in Example 5, may be employed in the present invention. Typical compounds that contain two sulfur-nitrogen ring systems are illustrated in the following formula:

wherein Y is Z and Z" each represent the atoms, preferably carbon atoms necessary to complete a ring system having up to members; and X has the same meaning given above and is preferably l In the above formula, the sulfur-nitrogen groups may be the same or different, i.e., I I

SX--N-- 1 and/or S-) l(N and Z and 2" may be the same or different. Preferably, the sulfur-nitrogen groups are both for example, derived from thiazolidine and/or benzothiazoline and preferably Z and Z" are the same, for example, both cyclic sulfur-nitrogen rings being derived from thiazolidine or benzothiazoline.

Typical linear sulfur-nitrogen compounds that may be used in the present inventior are illustrated in the following formulas: R (d) R2SXN/ R1 wherein R is hydrogen or a monovalent organic radical; R and R each are a monovalent organic radical; and X has the same meaning given above; and i wherein R is a divalent organic radical and R and X has the same meaning given above. In formulas (d) and (e) X is preferably The linear compounds, like the cyclic compounds of formulas (a) and (b), will be substituted with a group which upon cleavage of the parent compound will be released as a dye intermediate selected from an aldehyde and ketone and capable of reacting with a color-forming reagent to yield a complete dye. For example, analagous to the cyclic 1,3-sulfur-nitrogen compounds discussed above, linear 1,3-sulfur-nitrogen compounds may be substituted on the carbon atom common to the sulfur and nitrogen atoms with a hydrocarbon radical (or radicals) which upon cleavage of the parent compound will be released as an aldehyde (or ketone) that is substantially colorless. The hydrocarbon radical(s) may be linked directly to the carbon atom or linked indirectly thereto through a linking group. If it is desired to render the parent compound substantially non-diffusible in the processing composition, the parent molecule may be substituted with a bulky group or anchor or with several groups which together serve to immobilize the compound. Such immobilizing group or groups, e.g., may comprise the R substituents in formulas (cl) and (e).- Suitable hydrocarbon radicals, linking groups and immobilizing groups have been enumerated above. As discussed with respect to the cyclic compounds, the linear compounds also may contain more than one sulfur-nitrogen group. As an illustration, the R substituent of formulas (d) and (e) may comprise a second linear sulfur-nitrogen group, the same or different or a sulfur-nitrogen group included in a ring system.

In the various embodiments of the present invention, binderless silver halide layers may be used and silver halide emulsions other than those specified may be employed, such as, silver chloride, silver bromide, silver bromoiodide, silver chlorobromide and silver cholorobromoiodide. Rather than the conventional silver halide emulsions, direct positive silver halide emulsions may be employed. By using such an emulsion in the above Examples, a negative rather than a positive image may be produced in the photosensitive element. When the photosensitive element contains the color image to be viewed by transmitted light, the concentration of silver halide in the respective silver halide strata preferably is such as to produce, when fully developed, silver of low covering power, i.e., of low maximumdensity.

The support layers referred to may be selected from any of the various types of conventional materials employed and may comprise polymeric films of both the synthetic type and those derived from naturally occurring products. Suitable materials include polymeric materials derived from ethylene glycol terephthalic acid, vinyl chloride polymers, polyvinyl acetate, polyamides, cellulose derivatives, such as cellulose acetate, triacetate, nitrate, etc., regenerated cellulose, glass and so forth. It will be appreciated that a transparent material having the requisite clarity and other characteristics for viewing the image by transmitted light will be selected as the transparent support.

Where an image-receiving layer is employed, it may comprise dyeable polymers, such as, nylon, partially hydrolyzed polyvinyl acetate, and polyvinyl alcohol and may contain a dye mordant.

The expression color as used throughout the foregoing specification and in the appended claims is intended to include the use of aplurality of colors to obtain'black.

It will be appreciated that the photographic system of the presentinvention may be used to liberate intermediates other than those specifically mentioned and that the present system for releasing the same in an imagewisefashion may be used with film structures other than those illustrated. For example, in diffusion transfer film units the negative component comprising at least one light-sensitive layer and the positive component comprising an image-receiving layer may be separate elements as shown above which are: brought together during processing and thereafter either retained together as the final print or separated following image formation.

Rather than the photosensitive layer and the imagereceiving layer being in separate elements, they may be in the same element. In such a film unit, the imagereceiving layer is coated on a support and the photosensitive layer is coated on the upper surface of the image-receiving layer, The liquid processing composition is applied between the combined negativepositive element and a spreading sheet which assists in spreading the liquid composition in a uniform layer adjacent the surface of the photosensitive layer.

Illustrative of still other film units are those where the negative and positive components together may comprise a unitary structure, e.g., integral negativepositive film units wherein the negative and positive components are laminated and/or otherwise physically retained together at least prior to image formation. Generally, such film units comprise a plurality of essential layers includinga negative component comprising at least one light-sensitive layer, e.g., a silver halide layer and a positive component comprising an imagereceiving layer which components may be laminated together or otherwise secured together in physical juxtaposition-as a single structure. 'In the formation of color transfer images, the dye image-forming reagents may be in the negative component and form a diffusible dye capable of transferring to the image-receiving layer.

Included among such structures are those adapted for forming a transfer image viewable without separation, i.e., wherein the positive component containing the transfer image need not be separated from the negative component for viewing purposes. In addition to the aforementioned essential layers, such film units include means for providing a reflecting layer between the image-receiving and negative components in order reflecting agent included in the essential layers of the film unit or the reflecting agent may be provided subsequent to photoexposure, e.g., by including the reflecting agent in the processing composition.

These essential layers are preferably contained on a transparent support closest to the image-receiving layer and preferably include another support positioned on the opposed surface of the essential layers so that the layers are sandwiched or confined between the support members, at least one of which is transparent to permit viewing of the final image. Such film units usually are employed in conjunction with means, such as, a rupturable container containing the requisite processing composition and adapted upon application of pressure of applying its contents to develop the exposed film unit.

Since certain changes may be made in' the above products and processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is: v

l. A photographic process for preparing a dye image by reacting (a) a dye intermediate containing a carbonyl group selected from an aldehyde and a ketone with (b) a color-forming reagent to form a complete dye which comprises the steps of developing an exposed silver halide layer with an aqueous alkaline processing composition; forming as a function of development, an imagewise distribution of at least one of said dye intermediate and said color-forming reagent; and thereafter reacting said color-forming reagent with the carbonyl group of said dye intermediate to form a corresponding imagewise distribution of a complete dye.

2. A photographic process as defined in claim 1 wherein an imagewise distribution of a dye intermediate containing a carbonyl group selected from an aldehyde and'a ketone is formed as a function of development. I

3. A photographic process as defined in claim 2 wherein said dye intermediate is an aldehyde.

4. A photographic process as defined in claim 1 wherein said color-forming reagent is a methylene cou-' pler;

5. A photographic process for preparingadye image by reacting (a) a dye intermediate containing-a carbonyl group selected from an aldehyde and a ketone with (b) a color-forming reagent to form a complete dye including the steps of developing an exposed silver halide layer with an aqueous alkaline processing composition; forming in undeveloped areas an imagewise distribution of silver ions and/or soluble silver complex; contacting said imagewise distribution of silver ions and/or I said complex with a sulfur-nitrogen compound capable of undergoing cleavage in the presence of said silver ions and/or said complex to liberate a dye intermediate containing a carbonyl group selected from an aldehyde and a ketone and thereby forming a corresponding group of said dye intermediate to form a complete dye,

said sulfur-nitrogen compound containing the group or wherein X is 6. A process as defined in claim wherein said processing composition is an aqueous alkaline solution of a silver halide developing agent.

7. A process as defined in claim 6 wherein said processing composition additionally contains a silver halide solvent.

8. A process as defined in claim 7 wherein a sheetlike element is in superposed relationship with a photosensitive element containing said silver halide layer and said processing composition is distributed in a substantially uniform layer between said photosensitive and sheetlike elements.

9. A process as defined in claim 8 wherein said compound is present in a layer in said sheetlike element.

10. A process as defined in claim 9 wherein said complete dye is non-diffusible in said processing composition.

ll. A process as defined in claim 10 wherein said color-forming reagent is present in said layer containing said compound.

12. A process as defined in claim 11 wherein said compound contains the group S II\I 13. A process as defined in claim 12 wherein X is 14. A process as defined in claim 13 wherein said compound is a cyclic compound having a ring system containing up to 20 members and said group is included in the ring.

15. A process as defined in claim 14 wherein said compound is a thiazolidine compound and the dye intermediate released is an aldehyde.

16. A process as defined in claim 15 wherein said color-forming reagent is a methylene coupler.

17. A process as defined in claim 16 wherein said thiazolidine compound is 2-(p-dimethylaminophenyl)- 3-propylthiazolidine and said dye intermediate released is p-dimethylaminophenyl benzaldehyde.

18. A process as defined in claim 17 wherein said coupler is malononitrile.

19. A process as defined in claim 17 wherein said coupler is N-ethyloxindole.

20. A process as defined in claim 17 wherein said coupler is a-cyanoacetanilide.

21. A process as defined in claim 16 wherein said thiazolidine compound is 2,2'-(N-butylthiazolidyl) methane and said coupler is l,3-dimethylthiobarbituric acid.

22. A process as defined in claim 9 wherein said color-forming reagent is present in said processing composition.

23. A process as defined in claim 22 wherein said compound contains the group and said color-forming reagent is a methylene coupler.

24. A process as defined in claim 23 wherein said compound is 2-(p-dimethylaminophenyl)-3- propylthiazolidine and said coupler is N-methyl-apicolinium tosylate.

25. A process as defined in claim 5 wherein said compound is present in a layer in said photosensitive element and the dye formed is non-diffusible in said processing composition.

26. A process as defined in claim 25. wherein said color-forming reagent is present in said layer containing said compound.

27. A process as defined in claim 25 wherein said color-forming reagent is present in said processing composition.

28; A process as defined in claim 8 wherein said dye formed is diffu'sible in said processing composition and said sheetlike element comprises a dyeable stratum and at least a portion of said diffusible dye is transferred to said dyeable stratum to form a color transfer image thereon.

29. A process as defined in claim 28 wherein said color-forming reagent is present is said layer containing said compound.

30. A photographic product comprising a photosensitive element comprising a plurality of layers including a support; a silver halide emulsion in a layer on said support; in alayer on the same side of said support as said silver halide emulsion, a sulfur-nitrogen compound capable of undergoing cleavage in the presence of an imagewise distribution of silver ions and/or soluble silver complex to liberate a substantially colorlessdye intermediate containing a carbonyl group selected from an aldehyde and a ketone in an imagewise distribution corresponding to said imagewise distribution of silver ions and/or said complex; and a color-forming reagent in a layer on the sameside of said support as said layer of sulfur-nitrogen compound, said colorforming reagent being capable of reacting with thecarbonyl group of said dye intermediate to form a complete dye, and said sulfur-nitrogen compound containing the group S-XN= or I s XN wherein X is 31. A product as defined in claim 30 wherein said color-forming reagent is in said layer containing said compound.

32. A product as defined in claim 31 wherein said compound contains the group l 33. Aprod ubfa smned in claim 32 fiat-T11R61 compound is a thiazolidine.

34. A product as defined in claim 31 wherein said color-forming reagent is a methylene coupler.

35. A photographic product comprising first and second sheetlike elements, said first element comprising a plurality of layers including a support; a photosensitive silver halide emulsion in a layer on said support; in a layer in one of said first and second sheet-like elements, a sulfur-nitrogen compound capable of undergoing cleavagein the presence of an imagewise distribution of silver ions and/or soluble silver complex to liberate a substantially colorless dye intermediate containing a carbonyl group selected from an aldehyde and a ketone in an imagewise distribution corresponding to said distribution of silver ions and/or said complex; means for applying a photographic processing composition comprising anaqueous alkaline solution of a silver halide developing agent and a silver halide solvent in a substantially uniform layer between said emulsion layer and said second sheetlike element in supers posed relationship therewith; and a color-forming reagent in one of said sheetlike elements or in said processing composition, said color-forming reagent being capable of reacting with the carbonyl group of said dye intermediate to form a complete dye, and said sulfur-nitrogen compound containing the group app. also 36. A product as defined in claim 35 wherein said compound contains the group 38. A product as defined in claim 35 wherein said compound is present in a layer in said second element.

39. Realm as aensea ire 1511i"?Waterman color-forming reagent is present in said layer containing said compound.

40. A product as defined in claim 35 wherein said compound is a thiazolidine.

44. A product as defined in claim 43 wherein said color-forming reagent is a methylene coupler.

45. A product as defined in claim 44 wherein said thiazolidine is 2-(p-dimethylaminophenyl)-3- propylthiozolidine.

46. A product as defined in claim 45 wherein coupler is malononitrile.

47. A product as defined in claim 45 wherein coupler is a-cyanoacetanilide.

48. A product as defined in claim 45 wherein coupler is N-ethyloxindole.

49. A product as defined in claim 45 wherein coupler is N-methyl-a-picolinium tosylate.

50. A product as defined in claim 44 wherein thiazolidine is 2,2'-(N-hutylthiazolidyl) methane said coupler is 1,3 -dimethylthiobarbituric acid.

51. A product as defined in claim 37 wherein said dye intermediate and said color-forming reagent form a dye diffusible in said processing composition, and said second element comprises a dyeable stratum so positioned as to be capable of receiving by diffusion transfer an imagewise distribution of said diffusible dye formed by reaction of said dye intermediate and said color-forming reagent.

said

said

said

said

said and 

1. A photographic process for preparing a dye image by reacting (a) a dye intermediate containing a carbonyl group selected from an aldehyde and a ketone with (b) a color-forming reagent to form a complete dye which comprises the steps of developing an exposed silver halide layer with an aqueous alkaline processing composition; forming as a function of development, an imagewise distribution of at least one of said dye intermediate and said color-forming reagent; and thereafter reacting said color-forming reagent with the carbonyl group of said dye intermediate to form a corresponding imagewise distribution of a complete dye.
 2. A photographic process as defined in claim 1 wherein an imagewise distribution of a dye intermediate containing a carbonyl group selected from an aldehyde and a ketone is formed as a function of development.
 3. A photographic process as defined in claim 2 wherein said dye intermediate is an aldehyde.
 4. A photographic process as defined in claim 1 wherein said color-forming reagent is a methylene coupler.
 5. A photographic process for preparing a dye image by reacting (a) a dye intermediate containing a carbonyl group selected from an aldehyde and a ketone with (b) a color-forming reagent to form a complete dye including the steps of developing an exposed silver halide layer with an aqueous alkaline processing composition; forming in undeveloped areas an imagewise distribution of silver ions and/or soluble silver complex; contacting said imagewise distribution of silver ions and/or said complex with a sulfur-nitrogen compound capable of undergoing cleavage in the presence of said silver ions and/or said complex to liberate a dye intermediate containing a carbonyl group selected from an aldehyde and a ketone and thereby forming a corresponding imagewise distribution of said dye intermediate; and reacting said color-forming reagent with the carbonyl group of said dye intermediate to form a complete dye, said sulfur-nitrogen compound containing the group -S-X-N or wherein X is
 6. A process as defined in claim 5 wherein said processing composition is an aqueous alkaline solution of a silver halide developing agent.
 7. A process as defined in claim 6 wherein said processing composition additionally contains a silver halide solvent.
 8. A process as defined in claim 7 wherein a sheetlike element is in superposed relationship with a photosensitive element containing said silver halide layer and said processing composition is distributed in a substantially uniform layer between said photosensitive and sheetlike elements.
 9. A process as defined in claim 8 wherein said compound is present in a layer in said sheetlike element.
 10. A process as defined in claim 9 wherein said complete dye is non-diffusible in said processing composition.
 11. A process as defined in claim 10 wherein said color-forming reagent is present in said layer containing said compound.
 12. A process as defined in claim 11 wherein said compound contains the group
 13. A process as defined in claim 12 wherein X is
 14. A process as defined in claim 13 wherein said compound is a cyclic compound having a ring system containing up to 20 members and said group is included in the ring.
 15. A process as defined in claim 14 wherein said compound is a thiazolidine compound and the dye intermediate releaseD is an aldehyde.
 16. A process as defined in claim 15 wherein said color-forming reagent is a methylene coupler.
 17. A process as defined in claim 16 wherein said thiazolidine compound is 2-(p-dimethylaminophenyl)-3-propylthiazolidine and said dye intermediate released is p-dimethylaminophenyl benzaldehyde.
 18. A process as defined in claim 17 wherein said coupler is malononitrile.
 19. A process as defined in claim 17 wherein said coupler is N-ethyloxindole.
 20. A process as defined in claim 17 wherein said coupler is Alpha -cyanoacetanilide.
 21. A process as defined in claim 16 wherein said thiazolidine compound is 2,2''-(N-butylthiazolidyl) methane and said coupler is 1,3-dimethylthiobarbituric acid.
 22. A process as defined in claim 9 wherein said color-forming reagent is present in said processing composition.
 23. A process as defined in claim 22 wherein said compound contains the group and said color-forming reagent is a methylene coupler.
 24. A process as defined in claim 23 wherein said compound is 2-(p-dimethylaminophenyl)-3-propylthiazolidine and said coupler is N-methyl- Alpha -picolinium tosylate.
 25. A process as defined in claim 5 wherein said compound is present in a layer in said photosensitive element and the dye formed is non-diffusible in said processing composition.
 26. A process as defined in claim 25 wherein said color-forming reagent is present in said layer containing said compound.
 27. A process as defined in claim 25 wherein said color-forming reagent is present in said processing composition.
 28. A process as defined in claim 8 wherein said dye formed is diffusible in said processing composition and said sheetlike element comprises a dyeable stratum and at least a portion of said diffusible dye is transferred to said dyeable stratum to form a color transfer image thereon.
 29. A process as defined in claim 28 wherein said color-forming reagent is present is said layer containing said compound.
 30. A photographic product comprising a photosensitive element comprising a plurality of layers including a support; a silver halide emulsion in a layer on said support; in a layer on the same side of said support as said silver halide emulsion, a sulfur-nitrogen compound capable of undergoing cleavage in the presence of an imagewise distribution of silver ions and/or soluble silver complex to liberate a substantially colorless dye intermediate containing a carbonyl group selected from an aldehyde and a ketone in an imagewise distribution corresponding to said imagewise distribution of silver ions and/or said complex; and a color-forming reagent in a layer on the same side of said support as said layer of sulfur-nitrogen compound, said color-forming reagent being capable of reacting with the carbonyl group of said dye intermediate to form a complete dye, and said sulfur-nitrogen compound containing the group -S-X-N or wherein X is
 31. A product as defined in claim 30 wherein said color-forming reagent is in said layer containing said compound.
 32. A product as defined in claim 31 wherein said compound contains the group .
 33. A product as defined in claim 32 wherein said compound is a thiazolidine.
 34. A product as defined in claim 31 wherein said color-forming reagent is a methylene coupler.
 35. A photographic product comprising first and second sheetlike elements, said first element comprising a plurality of layers including a support; a photosensitive silver halide emulsion in a layer on said support; in a layer in one of said first and second sheet-like elements, a sulfur-nitrogen compound capable of under-going cleavage in the presence of an imagewise distribution of silver ions and/or soluble silver complex to liberate a substantially colorless dye intermediate containing a carbonyl group selected from an aldehyde and a ketone in an imagewise distribution corresponding to said distribution of silver ions and/or said complex; means for applying a photographic processing composition comprising an aqueous alkaline solution of a silver halide developing agent and a silver halide solvent in a substantially uniform layer between said emulsion layer and said second sheetlike element in superposed relationship therewith; and a color-forming reagent in one of said sheetlike elements or in said processing composition, said color-forming reagent being capable of reacting with the carbonyl group of said dye intermediate to form a complete dye, and said sulfur-nitrogen compound containing the group -S-X-N or wherein X is
 36. A product as defined in claim 35 wherein said compound contains the group
 37. A product as defined in claim 35 wherein said compound is present in said first element in a layer on the same side of said support as said silver halide emulsion layer.
 38. A product as defined in claim 35 wherein said compound is present in a layer in said second element.
 39. A product as defined in claim 35 wherein said color-forming reagent is present in said layer containing said compound.
 40. A product as defined in claim 35 wherein said color-forming reagent is present in said processing composition.
 41. A product as defined in claim 36 wherein X is
 42. A product as defined in claim 41 wherein said compound is a cyclic compound having a ring system containing up to 20 members and said group is included in the ring.
 43. A product as defined in claim 42 wherein said compound is a thiazolidine.
 44. A product as defined in claim 43 wherein said color-forming reagent is a methylene coupler.
 45. A product as defined in claim 44 wherein said thiazolidine is 2-(p-dimethylaminophenyl)-3-propylthiozolidine.
 46. A product as defined in claim 45 wherein said coupler is malononitrile.
 47. A product as defined in claim 45 wherein said coupler is Alpha -cyanoacetanilide.
 48. A product as defined in claim 45 wherein said coupler is N-ethyloxindole.
 49. A product as defined in claim 45 wherein said coupler is N-methyl- Alpha -picolinium tosylate.
 50. A product as defined in claim 44 wherein said thiazolidine is 2,2''-(N-butylthiazolidyl) methane and said coupler is 1,3-dimethylthiobarbituric acid. 